Details: In December 1985, 36-year-old trapper Mike Riemer took his girlfriend, Diana Robertson and their daughter, Crystal, into the woods near Tacoma, Washington to look for a Christmas tree. That afternoon, Crystal was later discovered wandering around a department store without her parents. She was later identified after her photo was placed in the newspaper and her maternal grandmother recognized her. Mike and Diana had vanished without a trace, and all Crystal could tell police is that "Mommy is in the trees". Two months later, Diana's body was found deep in the forest around Elbe, Washington. She had been stabbed seventeen times and had a tube sock tied around her neck and there was no sign of Mike. His truck, which was nearby, had blood stains on the front seat and note on the dashboard that read, "I love you, Diana." Although her mother believed that it was his handwriting, it could not be confirmed. Police believe he is responsible for her murder as well as a double one that occurred in the same woods four months earlier. A man named Stephen Harkins was found shot to death in his sleeping bag. His companion, Ruth Cooper, was found two months later. They were camping in the same area where Mike set his traps. Both Ruth and Diana had been killed with the tube sock tied in the same way. Police considered two theories; the first was that an unknown serial killer had killed both couples, and then hid Mike's body. The other theory was that Mike himself was the serial killer. He apparently had a history of domestic violence, and this, along with other evidence, was enough for police to issue a warrant for his arrest. Police have never been able to determine if he is alive or dead, or if he was the killer or a victim. He is 6'0" and 180 pounds, has blue eyes, brown hair, a scar on his upper lip, and is a skilled outdoors man who may be living off the land. He has never been found and the murders remain unsolved.Extra Notes: This case first aired on the September 6, 1989 episode.Results: Unresolved. In March 2011, a skull found by hunters just one mile from where Diana's body was found was identified as Mike's. The cause of his death is publicly unknown. Police have since ruled him out as a suspect in the double murder, and authorities now believe that an unknown serial killer may be responsible for the Harkins/Cooper and Robertson/Riemer murdersLinks: None